How many time have you forgotten to turn off you turn signal?
On my bike, '03 Intruder, the blinking indicator is out of my field of view and I'm a bit forgetful and don't always remember to hit the cancel button.
I had on my previous bike a turn signal beeper that audibly reminded me of my turn signal be on. I liked it so well, I've just ordered one for my Intruder.
There are signal canceling devises available. Their price is pretty steep.
The beeper is about 1/3 of the cost of the canceling units and serves the purpose perfectly.

I actually don't do that :P (a lil OCD I am) whenever I'm riding I constantly find myself pushing the button in the make sure my signal is off ^_^ even when there is absolutely no reason to (like I've been driving straight for the past ten minutes)

I've made it a habit to press the canceler after I've gone around any bend regardless of whether I've used the signal or not. Do I still leave the signal on sometimes? Of course I do but I usually catch it eventually.

I'm always forgetting to turn off my signal also. I was going to purchase one from JC Whitney but didn't want to spend over $30. So I built my own for under $10. Takes only two parts from Radio Shack, a beeper and a bridge rectifier. Takes only 5 minutes to build. It took longer to trace and find the +side of my signal than it took to build. I installed my buzzer behind one of my side panels...works great

Radio Shack has a buzzer that is 110 db. When I first started to build my TS beeper I bought one. I was in the garage with the door closed and my kids were in the house and they heard it. My garage is about 100 yards from the house. I retuned it and bought an 87db....works perfect.